Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
thuc va » thuc vat, thuc dan, thuc day
ky sang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
va tinh » may tinh
di cua » doi cua, de cua, do cua
su xac » pu xac, su cac
xac ky » cac ky, sac ky, bac ky
le na » le nam, le va, le ta

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky sang mai hoi. hieu ((le na) or (ly nam)) thuc va tinh ((di cua) or (dai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky sang mai hoi. hieu ((le na) OR (ly nam)) thuc va tinh ((di cua) OR (dai cua)) viet.
• Adding a wildcard symbol may retrieve word variants: su xac ky sang mai hoi. hieu ((le na) or (ly nam)) thuc va tinh ((di cua) or (dai cua)) viet*.